Page 189 - Offshore Electrical Engineering Manual

176 CHAPTER 16 Transformers

FIGURE 2.16.4
Oil-filled transformer.
Courtesy OTDS.

TRANSFORMER REGULATION
It is important to ensure that the secondary voltage of the transformer does not drop
below the specified range, and therefore the transformer regulation needs to be
checked, based on the reactance and expected maximum loading, as follows:

I 1 (Re . cosΦ 2 + Xe . sinΦ 2 )
V pu =
V 1
where E , primary electromotive force (EMF).; E , secondary EMF; I , primary
1
2
1
current; I , secondary current; R , no-load resistance; V , primary voltage; V , sec-
o
1
2
2
ondary voltage; X , equivalent reactance of the primary and secondary windings
e
referred to the primary circuit; X , no-load reactance; Z , equivalent impedance of
o
e
the primary and secondary windings referred to the primary circuit; Ф , phase angle
1
between I and V and Ф , phase angle between I and V .
1
1
2
2
1